<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<body>

      <div id="app">
        <cpn1></cpn1> 
        <cpn2></cpn2>

      </div>
      <script src="../js/vue.js"></script>
      <script>

          // 子组件
          const cpnC1=Vue.extend({
            template:`
            <div>
                <h2>是我11</h2>
            </div>
            `
          })

          // 父组件
          const cpnC2=Vue.extend({
            template:`
            <div>
                <h2>是我22</h2>
                <cpn1></cpn1>
            </div>
            `,
            components:{
              cpn1:cpnC1
            }
          })

          // root 根组件
          var app=new Vue({
             el:'#app',
             data:{},
             methods:{},
             components:{
               cpn2:cpnC2
             }
          });
      </script>
  
</body>
</html>